This chapter provides an overview of William of Ockham’s theory of obligationes, a type of logical disputation developed in the twelfth century, popularized in the thirteenth century and persisting into the Renaissance, as it is found in Part III-3, chapters 39–45, of the Summa Logicae. Ockham discusses six types of obligationes: positio, depositio, dubitatio, impositio, petitio, and sit verum, with a focus on positio. In this chapter I show how Ockham’s theory fits into the history of the development of obligationes, and then discuss, in depth, each of the six types. I highlight some of the distinctive, and in some cases puzzling, aspects of Ockham’s theory.